Electronics > Beginners
Modern way to specify values on schematics
bsfeechannel:
--- Quote from: bson on March 04, 2019, 11:51:45 pm ---Once upon a time people made photocopies of schematics. Things like connection dots and periods in numbers risked being dropped by an unfortunate blank spot in the copy. By using notation like 2R2 consistently there was never a question of if that speck was a mangled period or just a bit of dirt.
We no longer do that; if I provide you with a schematic (it won't be on paper) and you worry about losing periods or connection dots in photocopies you're doing it wrong.
TL;DR: it's a workaround for a problem that no longer exists.
--- End quote ---
I don't think the problem has to do with printed or photocopied schematics. The way decimal separators and digit groupings are represented is different from country to country. So 123,456,789.0123 can be variously represented as
123.456.789,0123
123 456 789,0123
123'456'789.0123
123·456·789,0123
12,34,56,789.0123
depending where you are.
Using the prefixes leaves no margin for ambiguities.
filssavi:
--- Quote from: bsfeechannel on March 05, 2019, 12:32:28 am ---
--- Quote from: bson on March 04, 2019, 11:51:45 pm ---Once upon a time people made photocopies of schematics. Things like connection dots and periods in numbers risked being dropped by an unfortunate blank spot in the copy. By using notation like 2R2 consistently there was never a question of if that speck was a mangled period or just a bit of dirt.
We no longer do that; if I provide you with a schematic (it won't be on paper) and you worry about losing periods or connection dots in photocopies you're doing it wrong.
TL;DR: it's a workaround for a problem that no longer exists.
--- End quote ---
I don't think the problem has to do with printed or photocopied schematics. The way decimal separators and digit groupings are represented is different from country to country. So 123,456,789.0123 can be variously represented as
123.456.789,0123
123 456 789,0123
123'456'789.0123
123·456·789,0123
12,34,56,789.0123
depending where you are.
Using the prefixes leaves no margin for ambiguities.
--- End quote ---
why would you need so many digits though that is the whole reason to use SI prefixes
Also are you really specifying 1Mohm resostors(for example) down to the single ohm? That seems a bit unnecessary
Wimberleytech:
--- Quote from: bsfeechannel on March 05, 2019, 12:32:28 am ---
--- Quote from: bson on March 04, 2019, 11:51:45 pm ---Once upon a time people made photocopies of schematics. Things like connection dots and periods in numbers risked being dropped by an unfortunate blank spot in the copy. By using notation like 2R2 consistently there was never a question of if that speck was a mangled period or just a bit of dirt.
We no longer do that; if I provide you with a schematic (it won't be on paper) and you worry about losing periods or connection dots in photocopies you're doing it wrong.
TL;DR: it's a workaround for a problem that no longer exists.
--- End quote ---
I don't think the problem has to do with printed or photocopied schematics. The way decimal separators and digit groupings are represented is different from country to country. So 123,456,789.0123 can be variously represented as
123.456.789,0123
123 456 789,0123
123'456'789.0123
123·456·789,0123
12,34,56,789.0123
depending where you are.
Using the prefixes leaves no margin for ambiguities.
--- End quote ---
I am a Texan (Remember the Alamo!), so it pains me to say this...Europeans got it right with the metric system and with the comma. It is the right thing to do. :phew:
bsfeechannel:
--- Quote from: filssavi on March 05, 2019, 12:55:14 am --- why would you need so many digits though that is the whole reason to use SI prefixes
Also are you really specifying 1Mohm resostors(for example) down to the single ohm? That seems a bit unnecessary
--- End quote ---
This is just to show how the use of decimal separators and digit grouping can be confusing.
--- Quote from: Wimberleytech on March 05, 2019, 01:19:58 am ---I am a Texan (Remember the Alamo!), so it pains me to say this...Europeans got it right with the metric system and with the comma. It is the right thing to do. :phew:
--- End quote ---
Howdy partner. Welcome to earth. A bizarre place where we can't even agree where to put our commas.
emece67:
.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version